I have read multlple times that autopsies on people in their 80's and older indicate new tooth growth in their gums. I personally experienced tooth regeneration in my upper gums. As our life expectancy increases, our bodies may be coded to generate new teeth. The new tooth has to make room in your gums and it may have to push the old tooth out of it's way, so it creates intense pressure and crazy intense pain. For me, this process took close to 2 years. I would compare it to wisdom teeth except I had a k9 come in, which is closer to the front part of my mouth.